x86/Intel: fix "near ptr" / "far ptr" handling

x86/Intel: fix "near ptr" / "far ptr" handling

Commit dc2be329b950 ("i386: Only check suffix in instruction mnemonic")
broke rejecting of these for floating point insns. Fix this by setting
the "byte" operand attribute, which will now (again) cause an error.

Furthermore the diagnostic for the "far ptr" case in general and for the
"near ptr" case in the non-float cases became "invalid instruction
suffix" instead of the intended "operand size mismatch". Fix this by
also setting the "tbyte" operand attribute (no insn template accepts
both byte and tbyte operands).